while the third, less correlated SNP, approaches significance; SNP 9, in that cluster, is also significant. At the 5′ end of GABRR1, 3 SNPs (25, 28, 29) are significantly associated with early onset (and several others are nearly significant), with some evidence for association with the COGA definition of dependence (Table 2, Figure 3). Three SNPs (36-38) at the 3′ end of GABRR2 (which is just upstream of the 5′ end of GABRR1, Figure 3) show evidence for association with all 3 phenotypes, particularly DSM-IV dependence. Two of these, including the cSNP at position 430, are in LD with the group of SNPs at the 5′ end of GABRR1 (28-32; Figure 3, inset). Thus these two groups of SNPs may represent a single finding. SNP 38 is not in LD with other SNPs, and is most significant for the early onset phenotype.
